Conventionally, a combination of a Fresnel lens sheet and a lenticular lens sheet has been used for a projector screen. In recent years, a demand for displaying merchandise information, advertisement, or the like by projection on a shop window of a department store or the like, a transparent partition of an event venue, or the like while maintaining the transparency thereof is growing. It is said that, in the future, a demand for a highly transparent projection type image display screen which is used for a head-up display, a wearable display, or the like will be further increasing.
However, since a conventional projector screen has a low transparency, there is a technical problem that such projector screen cannot be applied to a transparent partition, or the like. Therefore, various screens are proposed that are capable of attaining a high transparency. For example, there is proposed a reflection type screen characterized in that 7 parts by weight of an aluminum flake and 25 parts by weight of pearl pigment flakes, which are based on mica coated with titanium dioxide, are mixed and used as a filler for an ink which is printed or coated on a plastic film or a sheet to form a light reflection layer (see Patent Document 1). A reflection type screen for a projector is proposed, characterized in that an optical diffusion layer is provided on the substrate, comprising from 10 to 80 by weight of a flake-form aluminum paste of a non-refilling type as a light reflecting agent, based on 100 parts by weight of a binder resin, and additionally 50% by weight or more of a light diffusion agent based on the light diffusion agent (see Patent Document 2). Further, a reflection type screen is proposed, in which an optical diffusion layer is laminated on a light reflection substrate, formed by a continuous layer composed of a transparent resin and a dispersion layer composed of anisotropic transparent particles (see Patent Document 3).